Filament Winding

Filament winding is an automated composite process where resin-impregnated continuous fibers are precisely wound over a rotating mandrel to form high-strength hollow structures. Rooted in technical textiles, it transforms yarns and rovings into engineered composites, enabling controlled fiber orientation and superior performance in pressure, structural, and corrosion-resistant applications.

Step by Step Guide

  1. Continuous fibers are supplied from creels
  2. Fibers are impregnated with resin (wet or prepreg)
  3. Fibers are wound on a rotating mandrel at controlled angles
  4. Layers are built to required thickness
  5. Composite is cured (ambient/oven/autoclave)
  6. Mandrel is removed to obtain hollow structure

Material Used

Fibers

  • Glass Fiber (E-glass, S-glass)
  • Carbon Fiber
  • Aramid Fiber (Kevlar)
  • Basalt Fiber

Fabrics / Forms

  • Continuous rovings / tows
  • UD tapes
  • Narrow tapes / hybrid tapes

Resins

  • Epoxy (high performance)
  • Polyester (cost-effective)
  • Vinyl Ester (chemical resistance)
  • Phenolic (fire resistance)

Advantages

  • High strength-to-weight ratio
  • Precise fiber orientation (design flexibility)
  • Automated process → consistent quality
  • Low material wastage
  • Excellent pressure & corrosion resistance

Limitations

  • Limited to cylindrical or axi-symmetric shapes
  • High initial equipment cost
  • Complex geometries need hybrid processes
  • Skilled process control required

Applications & End Products

  • Pressure vessels (CNG, hydrogen cylinders)
  • FRP tanks & storage vessels
  • Pipes & pipelines
  • Drive shafts
  • Rocket motor casings
  • Wind energy components
  • Industrial rollers & poles

Selection Criteria

  • Product is cylindrical or hollow
  • Requires high internal pressure strength
  • Needs directional mechanical properties
  • Demands corrosion resistance & lightweight design
  • Suitable for medium to high production volumes
  • Fiber alignment is critical for performance